1. Field of the Invention
This invention relates generally to cutting by a rotary tool having a segmented disc slitting or slotting tool and more particularly to an apparatus for changing the rotary position of a slotter member and for changing the relative position between fixed and movable knives on the slotter member.
2. Description of the Prior Art
In the slotting of corrugated paperboard blanks it is customary to use three rotary slotting members on a shaft which have a fixed slotting knife and a movable slotting knife thereon to cut slots in the paperboard blank to produce the flaps necessary for forming a corrugated box in which items are to be packed. To form the flaps on a corrugated box blank one knife on the slotting member is used to form the front slots on the leading edge of the box blank passing under the slotting member and the other knife is used to form the slots on the trailing edge of the box blank. To insure that the same size flaps are produced on both the leading edge of the box blank and the trailing edge of the box blank, it is necessary that one knife of the slotting member be in register with the leading edge of the blank as it passes beneath the slotting member. If the leading knife does not register with the leading edge of the box blank, slots of different lengths will be formed on the leading and trailing edge of the box blank forming flaps of different lengths. In addition, one knife on the slotting member is movable so that the angle between the fixed knife and the movable knife can be varied. This is necessary to insure that slots of equal length are formed at the leading and trailing edges of the box blank when a box blank of different size is to be run.
Heretofore, various apparatuses have been used to register one knife of the slotting member with the leading edge of a box blank passing thereunder, and for changing the angle between the movable knife with the fixed knife on the slotting member to produce flaps of equal length when it is desired to change the size of the box blank being run. Such an apparatus is shown in H. D. Ward, Jr. Pat. No. 3,067,643 which utilizes gearing arrangements to produce registery and angle changing between the knives. These gearing arrangements such as shown in the Ward patent are extremely complex, massive, and expensive to produce. Such arrangements require many different gears and gear arrangements and as such require precision manufacturing. These systems, because they use so many gears, are extremely large and bulky. Consequently, the cost of such gear arrangements are extremely high and these costs are passed on to the customer. An apparatus which is relatively inexpensive, that utilizes relatively few gears, and is able to be confined to a relatively small area is needed. Since the above gearing arrangements are extremely complex, bulky, and expensive, it is still quite common not to use any type of gearing arrangement for changing the angle between the movable knife and the fixed knife. Thus, when it is desired to form the flaps on a box blank of different size than previously used, it is necessary to stop the operation and manually change the angle between the knives on each of the three slotting members. This method is not satisfactory since the operation of forming boxes must be stopped to change the knife angle which results in lost production time and because of human inaccuracies the angle between the knives on each slotter member may vary to a slight extent thus forming slots of different lengths on the trailing edge of the box blank which results in inferior boxes.
Another disadvantage in the Ward apparatus is that he uses hand-operated running registers to change the rotary position of the slotter member and to change the angle between the fixed and movable knives. Since the operator must take the time to adjust the registry by hand, it takes him away from his other duties and the master control panel that is used to indicate the status of other box making operations. In addition, Ward uses a control shaft external to the slotter heads and separate adjusting gears to change the knife angles on each slotter head. Thus, each adjusting gear must be individually adjusted by hand to the proper position to insure the same angle change is applied to each slotter member. Further, Ward uses the registry changing mechanism on one side of the slotter-scorer apparatus and the knife angle changing mechanism on the other side of the slotter-scorer apparatus. Thus, the machine operator must walk all the way around the machine each time he desires to make a change for each operation.